Printing plate and component for making the same



Patented May 12, 1942 rna'ra AND COMPONENT Foa MAKING rna slum-z PRINTING Hans Beck, Ludwigshafen-on-the-Rhinep and Walther Kuehne, Mannheim, Germany ors, by mesne assignments, to E. I. du

. a s Pont de Nemours and Compan Wilmington, Del.

No Drawing. rial No. 1939 Application January 22, 1940, se- 315,024. in Germany January 13,

4 Claims. (01. 101-395) I This invention relates to printing plates and other units made from superpolyamides.

It is known to make printing plates and components therefor, as for example clichs and' types, from organic plastic materials by pressureor injection-molding processes. The greater part of plastic materials, however, is not sufficiently resistant to heat and by reason of their inferior surface hardness is ,wom out in a pretty short time when printing big editions. The plates' must be resistant to cleaning agents such as petrol or benzene hydrocarbons applied after use and capable of being repeatedly re-cast and used again, like type metal or other printing metals. For these reasons cellulose derivatives orhardenable artificial resin compositions were unsuitable to' be generally adopted for practical use in the above field.

We have now found that superpolyamides, i. e. high-molecular condensation or polymerization products of the polypeptide type, capable of be ing drawn into threads, which are obtainable for example by heating -u.o'-dicarboxylic acids together with u.w'-diamines or the corresponding salts thereof, for example adipic acid and hexamethylenediamine, or by heating w-aminocarboxylicacids, for example r-aminocaproic acid, or lactames, for example caprolactame, are 'excellently suitable as materials for printing plates and component parts therefor. These materials, which may also be incorporated with fillers or pigments, are pale in color and hence facilitate the leg'lbility of the printing block. Their speciflcweight is only slightly above 1.

The superpolyamides may be used for the preparation of printing profiles of most elaborate design, individual types, composed types or cliches. They may be worked for this purpose P p y by injection-moulding, butcasting andpressure-moulding with suitable cutting tools, for example gravers. Even very thin lines, for example the finest lines ofetchings, may be reproduced with great sharpness.

After moulding they solidify very rapidly and then possess great toughness, strength :and surface hardness which properties remain constant over a temperature range of from about 50 to more than 200 C. For the said reason the printing plates are highly fracture-proof andthereforo thin printing plates may be easily flexed and impolyamides have the most desirable property of 3 mediately be used in rotary printing. Owing to their great surface hardness very large edition may be printed without the profll'es' of the types being markedly worn. out. The superpolyamides being insoluble in the standard solvents, the printing plates may also'wbe easily cleaned after use or when they are fouled up with printing ink. The cliches, printing, plates etc. after use may also be re-cast or moulded again. The superbeing non-inflammable chemicals.

What we claim is:

and resistant to, most 1. A printing form composed essentially of a sunerpolyamide.

. 2. A printing form composed essentially of polymeric hexamethylene adipamide.

3. A printing letter of a superpolyamide.

4. A printing letter type composed essentially of polymeric hexamethylene adipamide.

HANS BECK.

*WALTHER KUEHNE.

type composed 

